Nancy Pelosi speaks during a DCCC election watch party in Washington, DC on November 6, 2018.

By Zach Gibson/Getty Images.

With the midterm election over and the House set to fall back under Democratic control, Capitol Hill is already reorganizing itself in anticipation of a hellacious new reality. “Tomorrow will be a new day in America,” Nancy Pelosi declared on Tuesday night, shortly after Fox News, CNN, and other political scorekeepers made the call. “Today is about more than Democrats and Republicans,” she continued. “It is about restoring the Constitution’s checks and balances to the Trump administration.” The threat was not lost on Trump. “If the Democrats think they are going to waste taxpayer money investigating us at the House level, then we will likewise be forced to consider investigating them for all of the leaks of classified information, and much else, at the Senate level,” the president shot back on Twitter. “Two can play that game!”

Trump may sound defiant—may even welcome the chance to make Pelosi his foil for 2020—but inside the White House, advisers are justifiably depressed by the prospect of two (or more) years under the microscope of the House Oversight Committee. The Trump administration, after all, has produced scandals at an alarming rate, from a campaign that remains under investigation by the Justice Department to corruption investigations into a half-dozen Cabinet officials, to the firing of Jeff Sessions. Most controversies have been swept under the rug by Republican lawmakers who dutifully looked the other way. Now, Democrats are ready to make Trump’s life hell. “Congress is going to force transparency on this president,” one Democratic congressional aide told me. “Once there is transparency, I am sure there are going to be a lot of questions that flow from that.”

Wielding the power to subpoena documents, administration officials, and Trump associates, House Democrats can pursue any and all lines of inquiry their Republican colleagues ignored. And there will be little Trump can do to stop them. “It seems that the prospect of oversight and investigations has already gotten very much into the president’s head, since it was very much a focus of his election commentary,” Bob Bauer, who served as White House counsel to Barack Obama, told me. “The White House can be affected by these matters in a range of ways, including the way it staffs up, allocates resources, and sets legislative strategy, but the impact is magnified if the executive is obsessed with his perception of the threat, as he may already be.”

Impeachment—a liberal wet dream and Democratic Party nightmare—is on the back-burner for now, at least until Robert Mueller returns with his Russia report. Pelosi, who has been in Congress long enough to remember how the Clinton impeachment trials backfired for Republicans, said Tuesday that such a drastic move would “have to be bipartisan,” and that “the evidence would have to be so conclusive.” Congressman Jerrold Nadler, who is set to take over as chairman of the House Judiciary Committee, and would take the lead on initiating impeachment proceedings, released a statement promising “accountability” and “oversight,” but not much else. (On Wednesday afternoon, after Sessions was fired, he vowed to use his power to protect Mueller’s office from political interference.)

But there is much that is likely to happen in the meantime. California Congressman Devin Nunes, the bumbling, sycophantic chair of the House Intelligence Committee, will pass the gavel to ranking Democrat Adam Schiff, also of California, who has promised to deploy the full resources of the committee to get to the bottom of the Russia affair. He has also been forthright in his contempt for Nunes, who he accused on Tuesday of having run interference for the administration. “The majority went further by being complicit in the president’s attacks on the independence of the Justice Department, on the men and women of the F.B.I., on our intelligence community,” he said, after handily winning re-election in his district. “So we also need to restore the relationship between our committee and the intelligence community and law enforcement.”

Schiff has signaled the committee will wait for the special counsel’s office to deliver its findings in the Trump-Russia investigation, which is believed to be nearing its final stages. But there is no guarantee that even lawmakers will have access to Mueller’s eventual report on the investigation, given that he has no D.O.J. mandate to report to Congress—unlike Whitewater prosecutor Kenneth Starr. Even if Mueller’s report is made accessible, a number of questions could still go unresolved.

These lines of inquiry could include the Trump Organization’s finances—something that the new acting attorney general, Matthew Whitaker, has described as a “red line,” and which Mueller may not be investigating. “I don’t know whether Mueller has been able to answer [the following question], because I don’t know whether he’s been given the license to look into it,” Schiff told CNN’s Wolf Blitzer last month. “Were the Russians laundering money through the Trump Organization?” Another unresolved question is the name of the individual who called Donald Trump Jr., from a blocked number, in the midst of organizing the now infamous June 2016 Trump Tower meeting with Russian lawyer Natalia Veselnitskaya. Schiff toldThe Washington Post in April that Republican members of the House Intelligence Committee “refused” to subpoena the call. As chairman, Schiff could do so—and could also subpoena Don Jr. to appear before the committee again.

Republicans still have time to gum up the works, according to Democratic congressional aides. “We have about a month and a half, two months of a lame duck Congress under Republican control,” one told me. “There are a lot of things that could happen between now and when [Democrats] take the majority on January 3. Most specifically, there is a lot that can happen in the Mueller space, the special-counsel space. . . . Things are going to look so much different.” With Sessions getting the ax the afternoon after the midterm election, and Whitaker expected to take over the Russia probe from Rod Rosenstein, the White House still has plenty of power—and rope to hang itself with—before the Pelosi-Schiff regime begins.

A Democratic House, of course, will have plenty of instruments at their disposal to turn the screws, and more than one committee through which to do so. Kurt Bardella, who served as a spokesperson and senior adviser for the Oversight and Government Reform Committee from 2009 to 2013, predicted that Democrats would double the size of their staff after the House changes hands in January, with investigators and lawyers comprising the bulk of new hires. Congressman Elijah Cummings, the ranking Democrat who is expected to take over as chairman, has said he “will not be looking to make headlines.” But, like his fellow committee-chairs-in-waiting, his definition of the job presumes a mandate for revenge. “My aim is to do what I swore to do—uphold the Constitution,” Cummings said in a statement Tuesday. “We haven’t been doing that because Republicans have been aiders and abetters.”

With Democrats running O.G.R., top priorities will include lifting the veil on the Trump administration’s security-clearance process—bad news for Jared Kushner and Rob Portman, the former White House staff secretary—as well as the president’s financial conflicts. One potential avenue of inquiry will be Trump’s potential violations of the Emoluments Clause, as well as the alleged widespread corruption at government agencies and by administration officials, including Scott Pruitt, the former head of the Environmental Protection Agency, and Ryan Zinke, the secretary of the Department of the Interior.

Other House committees will coordinate with O.G.R., focusing on lines of inquiry that dovetail with its jurisdiction. For instance, the House Foreign Affairs Committee will likely investigate allegations in Foggy Bottom that Trump appointees targeted State Department employees based on their perceived political beliefs and ideologies—something, as I have previously reported, that Secretary Mike Pompeo has yet to answer for. The House Homeland Security Committee will likely probe issues including the administration’s response to Hurricane Maria, domestic terrorism, and election security, along with a bevy of controversial immigration measures such as family separations at the southern border, DACA, and the travel ban. “We will be doing the rigorous oversight the Republicans have not done and we have tried to do,” one of the Democratic congressional aides familiar with the plans told me. “Congress cannot be a rubber stamp for the administration.”

Then there’s the matter of Trump’s tax returns. With control of the House, Democrats can finally go after the president’s taxes under a 1924 law that allows the House Ways and Means Committee to inspect any taxpayer’s returns. The documents could shine a light on the president’s potential financial and foreign conflicts of interest, potentially prompting lawmakers to launch further investigations. On Tuesday night, MSNBC host Ari Melber reported that Democrats on the House Ways and Means Committee already intend to request the returns, as Congressman Richard Neal—who is in line to take over the committee—has previously signaled.

Of course, Trump isn’t likely to go down without a fight. “The White House would probably turn to fairly vigorous assertions of executive privilege in response to House investigations. That could in turn lead to contempt citations, and then fights over enforcing the contempt citations,” Josh Chafetz, a constitutional law professor at Cornell Law School, told me. “Those fights could play out in court, which is what has happened in the last couple administrations. But I’ve argued that Congress almost never gets what it really wants when it goes to court.”

Democrats will, however, need to be prudent in dissecting Trump. As the president has already demonstrated with his cynical branding of the Mueller investigation as a “witch hunt,” any perception of zealotry could backfire. “We don’t want to have committees stepping on each other’s toes and being duplicative and failing to coordinate. We also don’t want to be precipitous. We don’t want to conduct oversight the way the Republicans conduct oversight—which is a political circus or not at all,” the first Democratic congressional aide told me. “Democrats need to find that balance where we are being transparent and deliberate and operating in good faith about this stuff, because we don’t want it to be a political sideshow. We are going to be accused of running a political sideshow anyway, but the House oversight and investigations need to have credibility.”